Melbourne, March 6 (IANS): The United States on Sunday secured its place in the quarter-finals of the Davis Cup tennis tournament with a 3-1 win against Australia, after John Isner fought off a late challenge from Bernard Tomic to win 6-4, 6-4, 5-7, 7-6 here on Sunday.

After cruising through the first two sets with ease, the big serving American had silenced the crowd and looked to put the rubber away in straight sets, but a resilient and injured Tomic battled his way through the third, and took a rare break point opportunity to extend the match, reports Xinhua.

With the momentum on Tomic's side, he was clinical on serve in the fourth, but eventually lost an entertaining fourth set tie-breaker to a clinically serving Isner, who hit 49 aces in his dominant performance.

The win wrapped up a 3-1 victory in the tie for the US, which will host the winner of Croatia and Belgium in July. Team captain Jim Courier said it was important to get the win playing away from home, and praised Isner's "breathtaking" performance on serve.

Isner was spot on serve early in the rubber, not giving Tomic -- or the Australian crowd - a chance to get going. Frustrations were clearly on display from the Australian camp; after the first two sets, which Isner wrapped up in an hour, Tomic had only won five points on the American's serve.

Despite the dominance however, Tomic was able to keep himself in the match heading deep into the third. While he was holding serve nervously at times, Isner was holding with ease, until Tomic went up 6-5 in the set and was presented with just his first break point for the entire match.

Isner would go on to save five break points, however Tomic managed to scrap long enough for Isner to tire and make a couple of uncharacteristic unforced errors -- allowing the Australian to take the set and keep the rubber alive.

From there, the momentum seemed to shift and Tomic managed to kick up a gear. After receiving a medical timeout for his troublesome wrist and looking slow and lethargic around the court, the 23-year-old was moving swiftly and working the angles, and reversed the serve fortunes to not allow Isner a sniff during his service games.

After the pair forced a do-or-die tie-break for the Australian team, Isner once again found his automatic serve, and crunched a number of easy aces to deny the Australian and the parochial crowd a shot at a deciding fifth set.

Isner, the world No.11, said wrapping up the tie in four matches was a great relief for team US.

Meanwhile Australian captain Lleyton Hewitt said the Australian team, missing arguably two of its top three players in Nick Kyrgios and Thanasi Kokkinakis, struggled to settle.

"It was obviously pretty tough at times, with the late changes," Hewitt told the press on Sunday.